diff options
Diffstat (limited to 'runtime/protoimpl/version.go')
| -rw-r--r-- | runtime/protoimpl/version.go | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/runtime/protoimpl/version.go b/runtime/protoimpl/version.go new file mode 100644 index 00000000..ff094e1b --- /dev/null +++ b/runtime/protoimpl/version.go @@ -0,0 +1,56 @@ +// Copyright 2019 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package protoimpl + +import ( + "google.golang.org/protobuf/internal/version" +) + +const ( + // MaxVersion is the maximum supported version for generated .pb.go files. + // It is always the current version of the module. + MaxVersion = version.Minor + + // GenVersion is the runtime version required by generated .pb.go files. + // This is incremented when generated code relies on new functionality + // in the runtime. + GenVersion = 20 + + // MinVersion is the minimum supported version for generated .pb.go files. + // This is incremented when the runtime drops support for old code. + MinVersion = 0 +) + +// EnforceVersion is used by code generated by protoc-gen-go +// to statically enforce minimum and maximum versions of this package. +// A compilation failure implies either that: +// * the runtime package is too old and needs to be updated OR +// * the generated code is too old and needs to be regenerated. +// +// The runtime package can be upgraded by running: +// go get google.golang.org/protobuf +// +// The generated code can be regenerated by running: +// protoc --go_out=${PROTOC_GEN_GO_ARGS} ${PROTO_FILES} +// +// Example usage by generated code: +// const ( +// // Verify that this generated code is sufficiently up-to-date. +// _ = protoimpl.EnforceVersion(genVersion - protoimpl.MinVersion) +// // Verify that runtime/protoimpl is sufficiently up-to-date. +// _ = protoimpl.EnforceVersion(protoimpl.MaxVersion - genVersion) +// ) +// +// The genVersion is the current minor version used to generated the code. +// This compile-time check relies on negative integer overflow of a uint +// being a compilation failure (guaranteed by the Go specification). +type EnforceVersion uint + +// This enforces the following invariant: +// MinVersion ≤ GenVersion ≤ MaxVersion +const ( + _ = EnforceVersion(GenVersion - MinVersion) + _ = EnforceVersion(MaxVersion - GenVersion) +) |